A May wedding is being planned by Erin Ferguson of Butler and Derek Moffatt of Prospect. The bride-to-be is the daughter of Doug and Brenda Ferguson and Donna and Mike Osborne, all of Butler. Parents of the prospective bridegroom are Jim and Debbie Moffatt of Prospect. The bride-elect is a 2009 graduate of Slippery Rock High School and a 2011 graduate of Butler County Community College. Her fiancÚ graduated in 2004 from Slippery Rock High School. They are both employed in Butler.